Irritable Bowel Syndrome (IBS) is part of a spectrum of diseases known generally as Functional Gastrointestinal Disorders which include diseases such as non-cardiac chest pain, non-ulcer dyspepsia, and chronic constipation or diarrhoea. These diseases are all characterised by chronic or recurrent gastrointestinal symptoms for which no structural or biochemical cause can be found. Irritable bowel syndrome in the UK alone is responsible for 30-50% of all gastroenterology referrals to secondary care.
IBS is believed to be due to a number of factors such as physiological, emotional, cognitive and behavioural factors and is frequently encountered during periods of stress. Diagnosis of IBS is one of exclusion and is based on the observed symptoms in any given case. Commonly accepted criteria for IBS, known as the "Rome" criteria, include at least 3 months of continuous or recurrent symptoms of:
1. abdominal pain or discomfort that is relieved with defecation, and/or associated with a change in the frequency of stools, and/or associated with a change in the consistency of stool; and PA0 2. two or more of the following on at least a quarter of occasions: altered stool frequency, altered stool form, altered stool passage, passage of mucus, and/or bloating or feeling of abdominal distension. PA0 i) one or more vanilloid compounds, pharmaceutically acceptable salts, analogues and/or derivatives thereof, (component a); and PA0 ii) a pharmaceutically acceptable vehicle (component b), PA0 i) 0.01 to 300 mg of component a); PA0 ii) any one or more of PA0 iii) an enteric coating of from 1 to 500 .mu.m, all weights being per 1000 mg of composition. PA0 i) 0.01 to 300 mg component a); PA0 ii) any one or more of PA0 iii) an enteric coating of from 1 to 500 .mu.m, all weights being per 1000 mg of composition. PA0 i) 0.01 to 300 mg component a); PA0 ii) at least 0.1 to 999.99 mg of a pharmaceutically acceptable polymer gel; and PA0 iii) water, preferably deionised water, all weights being per 1000 mg of composition. PA0 i) 0.01 to 300 mg component a); and PA0 ii) any one or more of PA0 i) 0.01 to 300 mg component a); and PA0 ii) any one or more of PA0 iii) an enteric coating of from 1 to 50m, all weights being per 1000 mg of composition. PA0 i) 0.01 to 300 mg component a); and PA0 ii) any one or more of PA0 i) 0.01 to 300 percentage weight per volume (% w/v) component a); and PA0 ii) any one or more of PA0 iii) the balance being water, preferably deionised water. PA0 i) 0.01 to 300 mg component a); and PA0 ii) any one or more of PA0 0.1 to 999.99 mg cocoa butter, gelatin, glycerin and/or hydrogenated vegetable oils; and PA0 iii) the balance being water, preferably deionised water all weights being per 1000 mg composition.
Conventional treatments of IBS are based on the severity and the nature of each person's symptoms and whether or not any psychological factors are involved. Treatment of IBS may include one or more of the following: lifestyle changes, pharmacological treatment and psychological treatment. However, there is no general treatment which is applicable to all cases of IBS.
In certain cases, the exclusion of foods which aggravate IBS symptoms is recommended. However, this type of treatment is only effective when the underlying cause of IBS is related to diet.
Pharmacologically active agents are often used to treat IBS. Anti-diarrhoeals (for example, loperamide), smooth muscle relaxants (for example, mebeverine hydrochloride or alverine citrate), or antidepressants may be effective in treating IBS. However, there is no single pharmacologically active agent which is completely effective in alleviating the symptoms or curing TBS.
Psychological factors may be used in the treatment of IBS. Again, however, this treatment does not provide a universal cure for the symptoms of IBS since not all cases of IBS are due to psychological factors.
One method of treating pathological conditions of the small and large intestines is disclosed in U.S. Pat. No. 5,431,914. This patent discloses that the external application of capsaicin to the skin in specific regions affects certain nerves in the skin which lead to spinal cord segments. Thus, it is suggested that topical application of a dose of 0.03 mg capsaicin to the anterior and posterior divisions of spinal nerves T12 to S3 can be used to treat IBS. However, a clear mechanism of the mode of operation of this invention is not known.
Such a regime of self-administration is unlikely to be effective because the composition must be applied to a specific site which is not necessarily readily apparent to the patient. In addition, it is likely to be difficult to control the dosage when applying the composition of U.S. Pat. No. 5,431,914 since it is in the form of a topical cream.
A need therefore exists for a composition which is able to relieve the symptoms of irritable bowel syndrome which ideally is in a form which is easily handled, may be administered in a unit dosage form and which is capable of being self administered by patients.